>> reporter: decades later, they united as senators to resolve p.o.w. issues and normalize relations with vietnam. >> working toward that end with john and witnessing almost daily his exemplary statesmanship is one of the highest privileges i've had here. >> reporter: today, they do have differences. mccain is more willing to arm the rebels in syria. >> i think we ought to tell the syrian people that we're either going to help them or we're not. >> if you have a complete implosion of the state, nobody has clearer definition of how you put those pieces back together. >> reporter: he and others also pressed kerry on benghazi. >> are you willing to work with me or do you basically kind of agree hillary clinton that that's kind of yesterday's news and let's move on? >> well, senator, if you're trying to get some daylight between me and secretary clinton, that's not going to happen here today. >> reporter: kerry promised to stress economic issues, climate change and stop iran from getting a nuclear weapon. >> we will do what we must do to prevent iran from o